JP2528434Y2 - Drilling torque detector for rotary casing in drilling equipment - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drilling device for drilling a hole in the ground, and more particularly to a detecting device for detecting the drilling torque at the tip of a rotary casing used for drilling a large-diameter shaft.

[0002]

2. Description of the Related Art When excavating a large-diameter vertical hole in the ground, a drilling bit is provided at the tip of a rotary casing having an outer diameter corresponding to the inner diameter of the hole to be drilled, and the rotary casing is rotated while rotating. The pit is drilled into the pit and the earth and sand excavated by the excavation bit is discharged upward to drill a pit.

In such a drilling machine, the rotational torque fluctuates in accordance with the properties of the ground. Therefore, the rotational torque of the rotary casing is detected, and the press-fitting speed of the rotary casing, the necessity of water injection, and the like are determined in accordance with the torque. The excavation work is managed.

A conventional torque detecting means for a rotary casing measures a current value of a motor of a rotary drive device for rotatingly driving the rotary casing, and converts the current value into a torque to obtain the torque.

[0005]

However, in the above-mentioned conventional detecting means, the calculated rotational torque is the sum of the peripheral friction torque due to the rotation of the rotary casing and the excavation torque required for excavating the tip ground. There was a problem that it was not possible to make a distinction, so that only the tip excavation torque could not be known.

[0006] In view of the above, the present invention can accurately detect the excavation torque applied to the tip of the rotary casing, and can perform an appropriate excavation work in response to a change in the state of the tip ground. An object of the present invention is to provide an apparatus for detecting an excavating torque of a rotary casing in the apparatus.

[0007]

SUMMARY OF THE INVENTION In order to solve the problems of the prior art, the present invention has a rotary casing for drilling a hole in the ground, and a ground bit is formed by a drill bit at the tip of the rotary casing. In a drilling machine that excavates and drills a hole, a torque detector is fixed to the peripheral surface near the tip of the rotating casing at two locations spaced apart in the axial direction of the rotating casing, and the torque detection result by the torque detector And a calculation device for calculating the excavation torque at the tip based on the calculation.

[0008]

[Function] The rotary casing is driven to rotate and pressed into the ground,
Excavation is performed by excavating the ground with the excavation bit at the tip and discharging excavated earth and sand from inside the rotating casing. At this time, distortion in the torsional direction is generated in the rotating casing due to the resistance applied to the tip of the rotating casing. The distortion is detected by the torque detector, and the arithmetic unit calculates the excavation torque based on the detected value. From this calculation result, only the excavation torque at the tip of the rotating casing can be known, and when this value exceeds a set value, a warning is issued by a warning lamp or the like, so that a change in the ground can be notified. Then, the following measures can be taken promptly.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments shown in the drawings.

The embodiment shown in the drawings shows a case where the present invention is applied to a drilling device for excavating a vertical hole in the ground using a rotary casing 1, and FIG. 1 shows an overall view thereof, and FIG. FIG. 2 shows a cross-sectional view of the tip of the rotating casing 1.

In the drilling device, a driving unit 2 for applying rotation to the rotary casing 1 and press-fitting the rotary casing 1 is installed on the ground where a hole is to be drilled, and the rotary casing 1 is suspended in the drive unit 2 by a crane or the like. Rarely retained. The configuration of the drive unit 2 itself is generally known, and includes a base 4 installed on the ground 3, left and right pushing cylinders 5 and 5 established on the base 4, and the pushing cylinders 5 and 5. A gripping device 6 is configured to move up and down to grip the rotating casing 1, and the gripping device includes a pressing mechanism 8 at a plurality of inner circumferences of a ring member 7 that is fitted onto the rotating casing 1 as shown by phantom lines in FIG. , 8. The pressing mechanism grips the peripheral surface of the rotary casing 1, and the gear 9 on the outer periphery of the ring member 7 is rotated by a motor (not shown).
Are engaged with each other so as to rotate the rotary casing 1 via the ring member 7.

In FIG. 1, reference numeral 11 denotes a bucket elevator which is used as a means for discharging earth and sand excavated in the rotary casing 1 to the ground. The bucket elevator is suspended by a boom 12 of the bucket elevator 11 through a wire 13 via a wire 13. The bucket 14 is suspended from the upper end of the rotary casing 1 to scoop up the soil and the like in the rotary casing 1, pull it up, and discharge it to an appropriate place.

As shown in FIGS. 2 and 3, the rotary casing 1 has a double-pipe structure of an outer pipe 1A and an inner pipe 1B, and a ring head 15 is fixed to a tip thereof. Bits 16, 16 ... are provided around.

A required number (four in the figure) of strain gauges 17, 18,... As torque detectors are provided on the inner peripheral surface of the outer tube 1A of the rotary casing 1 near the ring head 15. Two strain gauges are fixed to each other at an angle of about 45 ° with respect to the axis at intervals in the direction, and each strain gauge is arranged to detect a strain in the torsion direction of the outer tube 1A. In the drawing, reference numerals 19 and 20 denote holes for mounting strain gauges provided on the inner tube 1B corresponding to the mounting positions of the strain gauges 17, 18,...
It is closed by 22.

The wiring 23 of the strain gauges 19 and 20 is
A and the inner tube 1B are guided to the upper end of the rotating casing 1 and are wirelessly transmitted to a receiver 25 through a transmitter 24 provided near the upper end of the rotating casing 1, and as shown in FIG. 26, and when the calculation result from the calculation device 26 exceeds the set value, it is input to a warning lamp 27, a display device 28, and a recording device 29 to warn and record the state.

In the figure, reference numeral 30 denotes a joint of the rotating casing 1, which is connected by fitting a joint pipe 1C at the upper end of the lower rotating casing 1 to a joint pipe 1D at the lower end of the upper rotating casing 1, and from the peripheral surface thereof. Plural taper pins 31, 31
... is fixed by hitting.

The calculation formula by the arithmetic unit 26 for converting the rotational strain from the detection result of the distortion of the rotary casing 1 by the strain gauges 17 and 18 and calculating the excavation torque at the tip based on the rotational torque is as follows. For convenience, a case where the calculation is performed based on two strain gauges 17 and 18 as shown in FIG. 2 is shown.

T _A : rotational torque detected by strain gauge 17 T _B : rotational torque detected by strain gauge 18 X: distance between strain gauges 17, 18 l ₁ : distance from tip to strain gauge 18 l ₂ ... when the distance from the tip to the strain gauge _{17, T B = T 1 +} l 2 circumferential surface resistance of the length X is T _X = T _B -T _a per unit length of the circumferential surface resistance t is, t = T _{X / X = (T B -T} a) / X drilling torque T ₁ of the _{tip, T 1 = T a -l ·} t = T a l 1 / X (T B -T a) and becomes the tip drilling torque T ₁ is calculated.

Therefore, it is possible to detect the digging torque of only the digging portion at the tip of the rotary casing 1 at the time of digging, and it is possible to appropriately cope with a change in the digging state.

[0020]

As described above, according to the present invention, the excavation torque at the tip of the rotary casing can be accurately measured even during the excavation work. This makes it possible to adjust the press-fitting speed of the rotary casing in accordance with the situation and immediately take measures such as the necessity of water injection, which is extremely effective in managing excavation work.

[Brief description of the drawings]

FIG. 1 is a side view showing an example of a drilling machine to which the present invention is applied.

FIG. 2 is a sectional view of a tip portion of the rotary casing showing one embodiment of the present invention;

FIG. 3 is a cross-sectional view of FIG.

FIG. 4 is an enlarged sectional view of a portion B in FIG. 2;

FIG. 5 is a control block diagram.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rotating casing 2 Drive part 4 Base 5 Push-in cylinder 6 Gripping device 7 Ring member 8 Pressing mechanism 11 Bucket elevator 14 Bucket 15 Ring head 16 Drilling bit 17, 18 Strain gauge as an example of torque detector 24 Transmitter 25 Receiver 26 arithmetic unit 30 joint

Claims (1)

(57) [Scope of request for utility model registration] 1. A drilling device having a rotary casing for drilling in the ground and drilling and drilling the ground with a drill bit at the tip of the rotary casing, wherein a peripheral surface at a position near the tip of the rotary casing is provided. A drilling device, comprising: a calculation device for fixing a torque detector at two locations spaced apart in the axial direction of the rotary casing, and calculating a drilling torque at the tip based on a result of torque detection by the torque detector. Excavation torque detection device for rotating casing in the device.